1. Field of the Invention
The present invention relates to flexible manufacturing systems using power conveyors to transport work between multiple work locations. More specifically, it relates to an improved apparatus and method of converting the power conveyors for improving the efficiency and usage factor of the machines located along a line in such a system. Such lines of machines, known generally as "production" or "assembly" lines, are old and well known and are used in many industries for improving efficiencies. By providing a means for converting a single long feed conveyor into two, oppositely running, feed conveyors, a larger portion of the machinery along such a line can be utilized simultaneously. It should be understood from the outset that the term "production line" as used herein is not necessarily confined to a straight line. Machines on such a production line are often arranged to go around corners or even arranged in curved patterns or circles. The word "line", in accordance with common terminology in this context, is applicable only in the sense that work proceeds sequentially from one machine to the next along the path of machinery.
This invention can be used in any industry in which sequential steps are used to produce or assemble a final product and a power conveyor can be used to carry the product from a location for performing one step to a location for performing the next step. Particularly large benefits can accrue in certain fields where each successive step is capable of being performed by similar or identical machinery and where that machinery is complex and expensive. Industries such as the the binding or "stitching" segment of the publishing industry are of such a nature. Because of the large potential savings, this industry has been chosen for the exposition of a preferred embodiment of the invention to follow.
Thus it can be seen that the potential fields of use for this invention are myriad and the particular preferred embodiment described herein is in no way meant to limit the use of the invention to the particular field chosen for exposition of the details of the invention.
A comprehensive listing of all the possible fields to which this invention may be applied is limited only by the imagination and is therefore not provided herein. Some of the more obvious applications are mentioned herein in the interest of providing a full and complete disclosure of the unique properties of this previously unknown general purpose article of manufacture. It is to be understood from the outset that the scope of this invention is not limited to these fields or to the specific examples of potential uses presented hereinafter.
2. Description of the Prior Art
Collating and binding systems are well known in the printing industry for mass producing booklets, magazines, catalogues, advertising brochures and the like. Typically, one or more sharply folded and generally pre-printed blanks or signatures (packets of individual sheets) are sequentially fed by a number of signature feeders. The signatures are delivered such that the signatures come to rest upon a collating conveyor line which travels past the signature feeders. The conveyor gathers the signatures, one atop another, and moves them to a binding, stitching, or stapling station. The assembled signatures then are usually diverted to a trimming station and further led to a labeling station where mailing labels are affixed.
Prior art systems of this type contemplate the computer controlled production of various demographic editions of books or catalogues of internal and external (cover) signatures containing individually tailored information or customized printing on selected signatures. This flexibility is important in satisfying the demands of a particular market or geographical destination. For instance, it may be desirable to offer certain customers or subscribers various features or selected advertising depending upon their special interest, income, or occupation. Likewise it may be relevant to customize products or services contingent upon a customer's previous buying history. As an example, a publication may issue one demographic edition for parents of newborn children who have purchased baby products, another edition for farmers interesed in the latest milking machines, and still another edition for fitness buffs who have ordered exercise equipment.
Machinery has even been developed which has redundant conveyors so as to feed signatures (packets of individual sheets) from an alternate source in case of malfunction in the primary source. The complex signature feeding machinery needed for such flexible binding jobs is very expensive with each station costing in excess of $30,000.
Devices for conveying work from one work station to the next are old and well known in the bookbinding art. Recently, technological advances in high speed printing have made it possible to print tremendous quantities of high quality printed sheets very rapidly. This in turn has led to the development of expensive, highly specialized machinery to form those sheets of printed matter into useful and saleable publications such as booklets and magazines as discussed above.
The following known prior art has been directed to providing some sort of conveyor apparatus for transporting printed matter to or from machinery used in the art of bookbinding. None of this prior art has taught the concept of providing flexibility to the bookbinding process by converting the conveyor apparatus so as to feed different machines nor so as to run in different directions. As will be seen, the simplicity and effectiveness of my invention is not rivaled in the prior art.
U.S. Pat. No. 5,232,324, issued to Graushar on Aug. 3, 1993, shows an apparatus and method for applying covers to books of signatures transported along a binding line. The apparatus includes cover feeders for feeding at least two covers upon a conveyor line and a fastening arrangement for joining the covers in substantially superimposed registration on the signatures at a covering station on the binding line. A spacer bar is supported on the conveyor line for temporarily separating the covers before they are joined to the signatures. The apparatus does not contemplate modification of the conveying means for different jobs as is shown by the instant invention.
U.S. Pat. No. 4,653,972, issued to Lewis on Mar. 31, 1987, shows a bookbinding machine which includes an advancing track of chain, a plurality of book clamps drivable by the chain successively to one or more processing stations, and means for arresting the movement of some of the clamps at some of the stations, while the other clamps remain in motion. By contrast, the device of the instant invention modifies the conveying means for different jobs.
U.S. Pat. No. 5,087,163, issued to Erbdories et al. on Feb. 11, 1992, shows a press for stitching book block sections which employs a transport system for transporting book sections to a stitching station. Carriages are mounted to an endless conveyor. A saddle is pivotally mounted to each of the carriages. The book sections are received on the saddle and transported to the stitching station in a continuous fashion. The pivotal swing of the saddles is controlled by rollers engaging cam paths as the conveyor is circulated. By contrast, the device of the instant invention modifies the conveying means for different jobs.
U.S. Pat. No. 4,704,973, issued to Horst on Nov. 10, 1987, shows a sewing press for thread-sewing book blocks which are formed from individual book block sections comprising an endless conveyor which transports the block sections into registration with a sewing head. The conveyor includes sewing saddles which support the block sections during sewing, the saddles being articulated to a continuously moving chain so as to have a dwell phase in the sewing region. The sewing needles, after punching the sewing thread through the block section, pivot to directly transfer the thread to the cooperating hook needles which, in turn, draw the thread back through the block section in the form of a loop which is linked to a loop on the preceding block section. By contrast, the device of the instant invention is not concerned with the details of a stitching or stapling operation and discloses a novel method of converting the power conveyor for use with different sized jobs.
U.S. Pat. No. 2,024,959, issued to Alger on Dec. 17, 1935, shows a bookbinding machine fed by a chain conveyor means operating with an intermittent movement. The chain is supported on and driven by sprockets as contemplated by my invention. The chain extends lengthwise of the machine and is provided, at intervals, with upstanding feeding lugs similar to those used by my invention. The feeding lugs act to insure proper guidance of the books. By contrast, the instant invention includes means to modify the chain conveyor and its driving mechanism so as to separately feed two lines of machines in opposite directions or, alternately, so as to feed a single line of machines in a single direction.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.